Like all the games, Pokémon Rumble U features a wide variety of Pokémon, in this case all 649 Pokémon. As such, the locations of these Pokémon is spread out with most Pokémon only appearing within a single location which means hunting down a certain Pokémon species could be problamatic. This page lists all the Pokémon (seperated by generation for ease of use), as well as the locations in which you find them